What Is the Role of the Load-Bearing Package in GRC Components? Design Specifications and Application Practice of Load-Bearing Packages

The load-bearing pad is a key load-bearing component in GRC elements, mainly used to reinforce the load-bearing capacity of connection points and weak areas, preventing damage caused by stress concentration. Scientific design and application of load-bearing pads is central to ensuring the structural safety of GRC elements. Drawing on 28 years of experience in element R&D, Qinglong explains their core functions and design essentials.

1. Core Functions of Load-Bearing Pads

Load-bearing pads serve multiple key functions and improve the overall performance of elements. The primary function is stress distribution: installing load-bearing pads at positions such as GRC hanger connections and embedded countersunk bolts disperses concentrated loads over a larger area, preventing local stress from exceeding the tensile strength of the base material. Qinglong's test data show that connection points equipped with load-bearing pads achieve a stress concentration factor reduction of more than 60%. The second function is enhanced load-bearing capacity: pads are made of high-grade GRC mortar plus a double-layer steel mesh, with compressive strength ≥30MPa and tensile strength ≥5MPa, increasing the load-bearing capacity of connection points by 2-3 times. In addition, load-bearing pads improve connection reliability by filling the gap between the element and the connector, ensuring uniform force transfer and preventing loosening and deformation, making them suitable for heavy-load scenarios such as large GRC curtain wall panels and special-shaped elements.

2. Design Specifications and Parameter Requirements for Load-Bearing Pads

Load-bearing pad design must follow strict specifications to ensure performance. Dimensional parameters: pad length ≥150mm, width ≥150mm, thickness 10-15mm greater than the element body; pads at hanger connections must cover the entire contact area of the hanger. Material requirements: use low water-binder ratio GRC mortar mixed with alkali-resistant glass fiber (content ≥1.5%) and a built-in Φ6 steel mesh (mesh spacing ≤50mm) to enhance tensile and shear capacity. Position design: pads must be placed in areas of maximum internal force, such as hanger installation points, corner areas, and around embedded rebar, at a distance of ≥50mm from the element edge to avoid edge effects. In the giant GRC ship elements of the Hainan Changying Global 100 project, Qinglong ensured the safety and stability of heavily loaded areas through precise pad design.

3. Manufacturing and Installation Essentials for Load-Bearing Pads

Standardized manufacturing and installation are key to ensuring pad performance. Manufacturing stage: cast simultaneously with the GRC element, use high-frequency vibration to ensure compaction and avoid air bubbles and hollowing, and maintain humidity ≥90% during curing to ensure full strength development. Installation stage: the pad surface in contact with connectors must be flat and smooth to ensure a tight fit; when installing hangers, align them with the pad center to avoid eccentric loading. For pads made on site, first clean the element surface, apply a bonding agent to enhance adhesion, then cast the mortar in layers, each ≤50mm thick, compacted by vibration. Through standardized construction, Qinglong achieves a 99.5% qualification rate in pad production.

4. Application Scenarios and Practical Cases of Load-Bearing Pads

Load-bearing pads are widely used in various heavy-load and critical-position GRC elements. Large curtain wall panels: 150×150×30mm pads at the hanger positions of 20mm-thick GRC curtain wall panels, applied in the Shenzhen Longhua Xiangshan Science and Technology Park project. Special-shaped sculpture elements: ring-shaped pads at load-bearing positions of GRC sculptures over 3 meters to enhance overall stability, such as the Shanghai Astronomy Museum public art project. Corners and joints: triangular pads at the inner corners of exterior wall corner elements to distribute corner stress, applied in the Guangxi New Media Center project. Heavy-load elements: for GRC elements weighing over 100kg, pads are installed at every connection point to ensure load-bearing safety. Through targeted application, Qinglong effectively improves the load-bearing performance of various GRC elements and safeguards project safety.